The present invention relates to a device for use in the gearbox of an aircraft to help keep oil within the gearbox from leaking out into the atmosphere. During operation of the aircraft, pressures may build up within the gearbox. If these pressures are allowed to build up in excess, they may interfere with the normal operation of the various components of the gearbox. Accordingly, a vent usually is provided from the gearbox to relieve interior pressures.